Method for forming sealed hollow articles of glass



H. H. BLAU Feb. 27, 1940.

METHOD FOR FORMING SEALED HOLLOW ARTICLES OF GLASS Filed Sept. 8, 1957 2Sheets-Sheet 1 M 0 WM wi INVENTOR. A4 4 61% ATTORNEYS.

WI ESSES:

Feb. 21, 1940. H. H. BLAU 2,191,951

METHOD FOR FORMING SEALED HOLLOW ARTICLES 0F GLASS Filed Sept. 8, 1937 2Sheets-Sheet 2 jZ/TNESSES: INVE%OR.

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BY W/MWr M ATTORNEYS.

Patented Feb. 27, 1940,

PATENT. OFFlCE METHOD FOR FORMING SEALED HOLIiOW ARTICLES F GLASS HenryH. Blan, Charlerol, Pa., assignor to Corning Glass Works, Corning, N.Y., a corporation of New York Application September 8, 1937, Serial No.162,902

Claims. '(Cl. 49-82) This invention relates to methods for making sealedhollow bodies of glass, as for example,

1 of air or gases from the interior of the article.

hollow building blocks which now are being used in increased numbers forpartitions, walls, ceilings and the like, and more particularly isconcerned with commercially practical methods for producing sealedhollow glass bodies having a desired internal pressure.

Heretofore sealed hollow bodies or articles of glass, such as buildingblocks, usually have been made by press forming complemental partsgenerally in the form of halves having peripheral flanges boundingrelatively flat portions. The edges of the flanges of the press-formedparts have been heated to soften them and the parts have been pressedtogether to form a hollow body. While this procedure is generallysatisfactory, I have found that it is difllcult to obtain hollow glassbodies with desired internal pressures which is of considerableimportance. If the internal pressures are too low or too high, thebodies are weak structurally. I have found, moreover, that in makingglass bodies by the known process above described when the parts arefused together to form a sealed hollow article the gases entrappedbetween the halves are ordinarily not at the temperature of the glassparts so that once the gases have reached the glass temperature there isa considerable pressure inside the article which is often sumcient tocause a blowout of a weak or more fluid portion of the zone or line ofjoinder'of the parts.

It is the general object of my invention to avoid and overcome theforegoing and other objections by the provision of improved methods andapparatus particularly adapted to rapidly and efflciently manufacture incommercial production sealed hollow glass articles having a desiredinternal pressure under normal conditions of use.

Another object of my invention is the provision of a novel methodincluding the step of entrapping a desired amountof gas between theglass parts when joined together to form a sealed hollow body.

Another object of my invention is the provision of relativelyinexpensive substantially automatic apparatus for producing hollow glass.bodies having a desired internal pressure.

Another object of my invention is to provide a method for making sealedhollow articles of glass in which complemental parts are joined togetherby fusion with certain of the parts being vented to allow the escape ofa desired-amount The foregoing and other objects of my invention areachieved by the provision of a method for making sealed hollow articlesof glass from preformed parts, which method comprises holding the partsin alignment but spaced apart, simultaneously heating the portions ofthe parts to be engaged to soften them, bringing the parts almosttogether and so that the heated portions are in opposed and closelyspaced relation to each other, and holding the parts in the statedrelation for a predetermined dwell to allow a desired amount of the hotgases to escape from' between the glass parts. After the dwell, thesoftened portions of the parts are pressed together in fused relation toform a sealed hollow body. Instead of achieving the seal between thecomplementary parts by fusion of glass to'glass, I may seal two hotpreformed glass parts together by dipping the portions to be engaged inmolten metal, such as solder or aluminum, or by the use of othercements. The parts are thereafter brought together in fused relationafter a predetermined dwell so that the pressure in the interior of thehollow article is as desired.

Apparatus constructed in accordance with my invention includes means forsupporting preformed glass parts having portions to be engaged inspaced-apart relation, means for heating the portions to soften them,and means for bringing the parts into closely associated but spacedrelation to each other and for holding the parts there for apredetermined dwell. For completing the combination means are providedfor pressing the softened portions of the parts together in fusedrelation to form a sealed hollow article and for holding the parts insuch relation until fusion takes place.

In the accompanying drawings Fig. 1 is a vertical cross-sectional viewof one embodiment of apparatus incorporating the principles of and forpracticingmy invention; Fig. 2 is a vertical crosssectional view takenon line 11-11 of Fig. 1; Fig. 3 is a horizontal cross-sectional viewtaken on line III-III of Fig. 1; and Fig. 4 is a perspective view of aglass part preformed to shape principles are particularly beneficial inmaking hollow glass building blocks and hence the invention has been soillustrated and will be so described. However, it should be expresslyunderstood that my invention is not limited to the specific examplethereof described. Again, while the method. of my invention can beperformed by various apparatus as, for example, simple hand tools or anautomatic turret-type apparatus, I have illustrated one type ofapparatus for performing the method of my invention which will now bedescribed.

Having particular reference to Fig. 1, the numeral 38 indicatesgenerally a table having a central stud 32 which rotatably carries formovement in a horizontal plane a burner, indicated as a whole by thenumeral 36. The burner 36 is usually of the type adapted to burn a mix-.ture of air and a combustible gas and is provided with a plurality ofports 38 at its upper and lower surfaces which ports extend to a chamber40 provided in the interior of the burner and to which a conduit 42 isconnected for-supplying the fuel to theburner. An operating handle 44 onthe burner permits the burner to be swung about the stud 32 and to aplurality of working stations.

Ordinarily the working stations are two in number, as illustrated, andeach includes a chuck or holding member 58 mounted on the table 38 andadapted to releasably receive a glass part G to be joined to a similaror complemental part in the formation of the hollow glass article. A

kick-out plunger 52 is ordinarily provided in the holding member 58 forremoving the glass part G, as hereinafter described. In the embodimentof the invention illustrated each-glass part G is formed with asubstantially fiat portion bounded by an upstanding endless flangewhich, as shown in the drawings, is positioned by the holding member 50so that the flange is in closely spaced relation to the ports 38 in thebottom of the burner 36.

Each workingstation likewise includes an upright 56 secured to the tableand provided with a vertically extending groove 58 which slidably' larto or complemental with the glass part G received by the holding member58. The holding member 68 has, however, been illustrated as of thesuction cup type including a manifold opening connected to the face ofthe holding member by a plurality of openings 12. The manifold openingI0 communication with apassageway 14 for d in the plunger 66, whichpassageway is ected to a suction conduit I6 by way of a valve 18 so thatoperation of the valve release or clamps a glass part G in the holdingmem er 68 so that the flange of the glass part is in alignment with theports 38 in the top of the burner 36.

The vertical position of the plunger 68 may be controlled as desired butin the example of my invention illustrated this is achieved by providinga rack 82 on the back of the plunger 68, which rack is engaged by apinion 84 secured to a shaft 86 journaled in the upright and carrying anoperating hand wheel 88 at its end.

- The plunger 68 is provided with means for indicating when it is in theproper vertical posiand is provided with adjustable cap screws 94.

which engage with the upper end of the upright 56 to limit the downwardmovement of the plunger.

In the operation of the apparatus just described and in the practice ofmy improved method, a complemental pair of glass parts G is inserted inone pair of holding members 58 and 68. The glass part G received in thelower holding member 50 is held in position by gravity while the glasspart G received in the upper holding member 68 is held in position bysuction when the valve 18 is turned to the open position. With theplunger 60 in its uppermost position the burner 36 is swung about thestud 32 to position theports 38 of the burner opposite the flanges ofthe glass parts G which are to be fused together. The burner heats theportions of the glass parts to be engaged to soften them and bring themto fusing temperature, and the burner is then swung about the stud 32and in between a second pair of complemental glass parts carried by thesecond station. The glass parts which have just been heated at the firststation are then brought into closely spaced relation with each other bymoving the holding memher 68 and the plunger 60 downwardly throughoperation of hand wheel 88 until the mark 90 comes to the top of theupright 56. This position .of the parts is illustrated on the right handside of Fig. 1 whereas'the heating of the glass parts is shown at theleft hand side of Fig. 1.

After the glass parts have been retained for a predetermined time in theposition illustrated in the right hand side of Fig. 1 and so that adesired amount of gas has escaped from between the glass parts, theoperating wheel 88 is turned to lower the uppermost glassv part intoengagement with the lower glass part, which movement is limited by theengagement of the cap screws 94 with the upper end of the upright 56.The glass parts are held in pressed-together sealed relation until thesoftened contacting portions thereof have fused integrally with eachother, and the glass at the line of Joinder has set.

After the glass parts have been joined together as just described,thevalve I8 is turned to closed position which releases the uppermostglass part from the holding member 68 so that by lifting the kick-outmember 52 the completed glass block can be removed from the lowerholding member 58 and placed in the finishing lehr. It will b understoodthat as one 'set of glass parts is being heated at one station, a secondpair of glass parts at the second station is being brought together withthe predetermined dwell and pressing operation as just described, andthat after'a complete block has been formed and removed from theapparatus still another pair of complemental glass parts is placed inthe holding members from which the completed blockhas just been removedso that the operation can be performed continuously.

The dwell of ,the glass parts in closely spaced relation comprises animportant feature of my invention inasmuch as by controlling the time ofdwell I am able to control the internal pressure inthe completed blockor other article within limits so. as to provide the strongest type ofblock from a given weight of material while retaining v the advantagesof insulating characteristics of the block. I am also able to largelyeliminate blowout of the zone of joinder of the blocks as often occurredin prior practices. Generally speaking, the longer the time of dwell thegreater is the vacuum in the finished block. This is due to the factthat the gases trapped between the glass parts are initially relativelycool. However, since the glass parts are comparatively hot, havingusually just been transferred fromthe pressing apparatus with theirflanges thereafter being highly heated, there is a temperaturedifferential between the entrapped gass and the glass parts resulting ina relatively rapid heating of such gas. Asthe trapped gas gets hotter itexpands and escapes between the spaced flanges of the glass parts priorto fusing them tightly together. Usually in manufacturing blocks 8" x 8"x 4", approximately one to three seconds dwell of the parts is employedto obtain the desired internal pressure in the block. Needless to saythe temperature of .the glass parts, the temperature of the gasentrapped between the parts, the mass of the gas, and the mass of the'glass are all factors in determining the time of dwell. By controllingthe time of dwell I am able to provide uniform blocks or other articleshaving an internal pressure of within approximately one pound of thatset as a standard.

In addition to .providing a dwell of the glass parts when in closelyspaced relation and before fusing I may provide venting means in theblocks which effect substantially: the same result. I have specificallyillustrated in Fig. 4 of the drawings a glass part G formed with ventopenings, such as notches 54, in its flanges, which notches, in thejoining of the glass parts together, function to vent out gases trappedbetween the glass parts. While a plurality of notches 54 have been shownin Fig. 4, it should be appreciated that one or more notches in the formof half round, half square, undulating or like recesses, serrations orraised portions, can be formed on the edges of the flanges to achieve aventing effect. Such serrations if formed continuously over the entireedge ,of the "flange increase the exposed surface area of the flange sothat the flange may be more quickly and more highly heated andminimizesthe localizing of the cooling ac tion of the egress of relatively coldgases from within the block.

I may shape the flanges of the glass parts so est mechanical and thermalvalue.

If the notches are used the soft plastic edges of the flangesare broughtinto contact with each other with the notches open to permit a desired).amount of the hot internal gases, to escape through them. ;After asuitable dwell-for this purpose qthef parts are pressed firmly together.It should be understood instead of providing ade'finite period of dwellduring which the glass arts, areystationary relative to each otherinclo'sely spaced relation that I may achieve the same result bybringing the glass parts into closely spaced relation and then slowlymoving the parts into sealing relation with each other. The word dwell"as employed in the claims is intended to cover both the stationary dwelland the slow moving dwell unless otherwise particularly stated.

From the foregoing it will be recognized that the objects of myinvention have been achieved by the provision of improved methods andapparatus for manufacturing hollow bodies of glass in whichinternal-pressures of desired magnitude are obtained. The methods andapparatus adapt themselves to commercial production operations and areeasily operated and performed.

While in accordance with the patent statutes one embodiment of theapparatus of my invention and one manner of practicing the method of myinvention have been illustrated and described in detail, it should beappreciated that the invention is not limited thereto or thereby, but isdefined in the appended claims.

I claim: I

1. The method of making sealed hollow bodies of glass from preformedcomplemental parts which comprises holding the parts so that theportions of the parts to be engaged are in alignment but spaced apart,simultaneously heating the portions to be engaged to soften them, movingthe parts in a straight line toward each other until almost together andso that the heated portions are in opposed and closely spaced relationto each other, holding the parts in the stated relation for apredetermined dwell to allow a desired amount of the hot gases to escapefrom between the glass parts, and then continuing the straight-dinemovement of the parts toward each other to press the softened portionsof the parts together in fused relation to form a hollow body.

2. The method of making hollow blocks of glass from press-formedcomplemental parts which comprises holding the parts so that they can bemoved directly together without stopping the parts to change thedirection of movement, simultaneously heating the portions of the partsto be engaged to soften them, thereafter moving the parts toward eachother with a continuous -movement which would effect a joining operationbut deliberately stopping the joining movement when the parts are almosttogether and so that the heated portions to be engaged are in opposedand closely spaced relation to each other, holding the parts insubstantially the stated relation for a predetermined dwell to allow adesired amount of the hot gases to escape from between the glassparts,and thereafter continuing the direct joining movement of the parts topress the softened portions of the parts together in fused relation toform a sealed hollow block having a desired amount'of gas trappedtherein.

3. The method of making a closed hollow building block from a pair offlanged halves thereof formed by pressing molten glass, comprisingheating the edges of the fianges of both halves to a fusion temperaturewhile the glass remains hot from its forming operation, moving thehalves almost together and with their flanges sumcient ly closetogethe'r so that further movement together will not. trap anyadditional cool gas between the halves, holding thehalves with theirflange edges in said closely spaced proximity to each other for at.least one full secondwhile gas within and heated by the halves thermallyexpanels and flows outwardly between the flange edges, thereafterbringing the flange edges of the halves together, and pressing thehalves towards each other integrally to fuse said edges together.

4. The method of making a closed ,hollow building block from, a pair offlanged halves thereof formed by pressing molten glass, comprisingpreparing the edges of the flanges while the glass remains hot from itsforming operation so that they are adapted to be joined together, movingthe halves almost together and with their flanges sufliciently closetogether so that further movement together will not trap any additionalcool gas between the halves, holding the halves with their flange edgesin said closely spaced proximity to each other for at least one fullsecond while gas within and heated by the halves thermally expands andflows outwardly between the flange edges, thereafter bringing the flangeedges of the halves together, and pressing the halves towards each otherto join said edges together.

5. The method of making a closed hollow building block from a pair offlanged halves thereof formed by pressing molten glass, comprisingheating the edges of the flanges of both halves to a fusion temperaturewhile the glass remains hot from its forming operation, bringing thehalves towards each other with a movement which if continued wouldeffect a 'joining operation but stopping this movement when the flangesare almost joined together and are in closely spaced proximity, holdingthe halves for not less than one second with their flange edges in thestated proximity to each other while gas within and heated by the halvesthermally expands andflows outwardly between the flange edges, andthereafter continuing the joining movement to bring the flange edges ofthe halves together and pressing the halves towards each otherintegrally to fuse said edges together.

HENRY H. BLAU.

